C1 Flashcards
(21 cards)
What did Hans and Zacharias Janssen do?
Invented the first microscope, 20x power, two-lens system
What did Robert Hooke do?
Invented a three lens microscope system, published the Micrographia, coined cells
What did Antoni van Leeuwenhoek do?
First to see movements, named them animalcules
what is an achromatic lens?
developed to control the halo and improve resolution
Who was Francesco Redi?
First to question spontaneous generation, simple meat in jars experiment
Who was John Needlam?
Supported spontaneous generation, boiled chicken broth in a sealed flash, microorganisms still appeared
who was Lazzaro Spallanzani
Anti spon-gen, drew the air out of a flask before sealing it, no microorganisms grew
who was louis pasteur?
S-flask experiment
Who was Robert Brown?
Identified the nucleus
What did MJ Schleidan and Theodore Schwann do?
proposed that cells were the basic unit of life
cell theory states that:
- all living things are made of cells
- all life functions take place in cells
- all cells are produced from preexisting cells through cell division
what is brightfield microscopy?
when light passes directly through cells (cells are clear so scientists stain them)
what is Fluorescence microscopy?
makes specific parts of the sample glow with UV light
what is confocal microscopy?
when a laser concentrates light onto a specimen, reflecting through a pinhole and forming an image of a thin section of the microscope
who were James Hillier and Albert Prebus?
developed the first electron microscope
what is an electron microscope?
uses a beam of electrons that scatter when they hit electron-dense materials
What is a TEM?
- transmission electron microscope
- depends on a beam of electrons passes through a thin section of tissue embedded in plastic
- electrons that pass through fall onto a fluorescent screen, making an image
- must be operated in a vacuum
what is a SEM?
- scanning electron microscope
- specimens are fixed and covered in an electron-dense material (gold eg)
- microscope scans the surface with a sensor, picking up the electrons that bounce off
what two microscopes can reveal even smaller structures that the SEM and TEM?
Scanning Tunnelling Microscope and Atomic Force Microscope
how do open cells communicate?
messenger molecules exit the cell and attach to target cells
x-ray crystalllography?
uses x-rays to learn the details of molecular structure
